The site of phosphorylation of proteoglycans synthesized by the Swarm rat chondorosarcoma will be determined using a combination of isolation, chemical analysis of isolated components, methylation, perodate oxidation, gas-liquid chromatography with mass spectroanalysis. The nature of phosphorylation in a wide variety of other proteoglycans from different species and different tissues will be examined to determine the generality of this modification of proteoglycan. It will be related to a possible functional significance within the cell. Additionally, intracellular location of phosphorylation will be determined by subcellular fractionation of prelabeled proteoglycan molecules using isotopic precursors and the appropriate isolation techniques including polyclonal antibodies. Possible substrates for the phosphorylation for detection of the enzyme both in terms of its phosphate donor and its probable substrate would be examined.